If once all the doors were wooden, today most of the entrance doors to apartments and entrances, not to mention the gates of country houses, are made of metal. And not always their design allows the use of mortise locking devices; in such cases, an invoice lock is installed.
Advantages of rim locks
The rim lock for a metal door has several advantages that can shift the scale in its direction when choosing:
- Easy installation that does not require special skills and complex tools, that is, you do not always need to call a locksmith, and the owner may well install the lock himself.
- For installation, you do not need to open the frame, and in many cases the door leaf, while maintaining its protective functions as much as possible.
- Repair of locks that do not need to be removed from the cavity of the metal box is easier to perform, as, indeed,their replacement.
- The full thickness of the door locking device is protected from rough mechanical breaking. At the very least, it will not be possible to silently remove the lock or violate its integrity.
In addition, a flat sheet door structure (in the entrance, for example) can dictate its own conditions for installing a lock.
Disadvantages of rim locks
But, unfortunately, the ease of installation turns into the ease of unlocking the lock from inside the apartment without a key, if, suppose, the robbers managed to get into it through the window. And besides, the overhead lock for a metal door cannot be upgraded and changed to another design.
With the help of a pry bar or a hammer, such a locking device is easy to open if you are not afraid of noise.
Whatever their design, the appearance of the inside of the door with overhead locks is much less aesthetic (and you have to wipe the dust) than a smooth canvas.
Installing a rim lock
The door overlay lock, regardless of the model and design features, is installed on the inside of the door so that it completely protrudes above the door leaf (superimposed). To fix the case, a special bar is used, welded or bolted to the door.
In the bar or in the door leaf, if it is not there, holes are marked for the fasteners of the locking mechanism and the counterpart, as well as for the key. These holes are then carefully drilled.
Invoicethe lock of the simplest design is screwed to the door leaf from the inside with screws, and the bar of its inlet is installed on the outside. That's the whole installation of the padlock.
True, these are the main stages. And additional actions depend on the design features of the locking device, for example, the installation of handles or a cylinder.
Classification of overhead locks
Overhead locks are classified according to several criteria. And perhaps the most important of them is the degree of security of the castle.
According to the design features, the locks can be bolt or boltless, designed for left-hand or right-hand doors. Now you can choose a suitable padlock for a metal door without turning it upside down when installing it and then opening it in the opposite direction.
Locks can be double-sided, opening with a key from the outside and inside, or one-sided, which open with a key only from the outside. May have additional features, such as a latch, fixed or spring-loaded padlock.
The overhead locks are made from different materials, which affects not only the cost, but also the reliability and durability of the device.
Materials for making locks
When choosing locks, be sure to pay attention to what material they are made of. So, plastic ones are generally not suitable for heavy metal doors. Soft silumin or brass, brittle cast iron, although stronger than non-ferrous alloys, are also not a good choice.
Onthe door to the entrance, which should serve as protection even in severe frosts, the shockproof cast-iron lock becomes brittle in winter and can collapse from slight mechanical impact.
High-strength steels withstand both temperature extremes and shocks, and the locks made of them are highly resistant to burglary.
Classification of overhead locks by type of locking mechanism
By the type of locking mechanism, there are three types of locks, including overhead:
- Cylinder. In addition to simplicity and reliability, a big advantage is the easy repair of locks by replacing the larva (cylinder mechanism). The degree of protection of the castle depends on its complexity.
- Level locks. They are considered the most reliable. Suvalds are called curly plates located inside the castle. The more of them, the more reliable the lock. But the barbed keys that move the plates are quite large, as, indeed, are the locks themselves. Judging by the reviews, not everyone likes these bulky mechanisms on the inside of the door. Another disadvantage of lever locks is that they can only be opened from the inside with a key.
- Smartlocks. These modern mechanisms do not require keys. They open with a code, like many entrance doors. But the wear of the buttons from frequent pressing leads to the fact that the code is no longer a secret, and it has to be changed often.
Smartlocks, by the way, can be opened using a retinal pattern or a fingerprint. Most likely, such locks are suitable for safes - and only personal ones, but they are very expensive.
Classification by mode of action
According to the method of action, overhead locks can be divided into mechanical, which are most common today and are opened with keys, and electrical devices.
Electromechanical devices are the same code smartlocks. Such a lock consists of a door bill of lading from a shutter mechanism and a dashboard on which a programmed code is dialed. Its significant disadvantage is the dependence on the availability of electricity. Once you turn it off, the lock stops working, and the door remains open.
The same drawback is inherent in electromagnetic locks, which are everywhere installed on the door to the entrance in multi-storey residential buildings. The locking mechanism adjusts to the electromagnetic fields of the keys and opens as soon as the magnetic key is brought to the reader on the outer panel.
Cracking these locks without preparation is almost impossible, expensive equipment is needed to select the code.
Expensive electromechanical or magnetic locks can be powered by a battery mounted on the inside of the door. And then their main shortcoming is eliminated.
Lock security classes
There are four security classes for locks. They are determined not only by mechanical strength, which does not allow you to simply knock out the lock. By the way, many negative reviews about overhead locks are based on the experience of a distantand not very childhood, when it was possible, with a little effort, to knock out overhead locks on wooden doors that open inward. Modern metal doors open outward, and knocking out such a structure from a metal frame is almost impossible.
Another parameter that affects the security class is the degree of secrecy of the lock, that is, the ability to pick up a master key:
- First class security locks open in minutes. This is an English (or cruciform) castle.
- The second class includes locking mechanisms that can be opened in about 10 minutes, both silently and with the help of a power tool, no doubt attracting attention. If the security class is not indicated in the accompanying document, then the mark that the lock is suitable for interior and entrance doors already indicates this.
- The most demanded locking device, judging by the numerous reviews, is an overhead lock for a third-class metal door. The opening time of such a lock is from 15 to 30 minutes, and it cannot do without noise. In many models, additional protective pads are installed. Lever locks belong to this security class.
- Fourth class locking mechanisms can resist breaking from half an hour to three hours, depending on the degree of complexity of the lock and additional locks. They are used, for example, in safes and doors of premises, which are subject to increased protection requirements.
Primary padlock privacy
The secrecy of the castle includessecurity (protection against mechanical impact and hacking with a master key), the number of key and lock combinations, the wear resistance of the device and the likelihood of matching keys.
There are three levels of secrecy. The simplest locks made of low-strength materials with up to 10,000 possible combinations are classified as a low level of secrecy.
Average secrecy is already from 5 thousand to 5 million combinations. In such devices, the locking mechanism is made of high-quality materials, and manufacturers save on body and handle materials.
Locks for safes have the highest level of secrecy. They are protected from both mechanical impact and burglary, the materials are resistant even to acid, the key profile is very complex, there are up to a billion possible combinations of a key and a lock, the accuracy of manufacturing parts is high.
Safe rim locks
Locks for safes and valuables can be called the pinnacle of overhead locks for metal doors. They can be locked with a key and with a mechanical or electronic combination, with magnetic or biometric identification.
Mechanical locks are most often lever locks, the keys to them have two grooves. Less common are cylindrical or pump-action locks with diagonal notches on the bolt, coinciding with the notches of the key. When the key is pressed, its notches disengage the crossbars from the counterpart. The complex geometry allows the lock to be opened only if the notches match perfectly.
Electronic locks allow you to complicate the keys and increase the number of operations or bind work witha safe to a specific artist with certain biometric indicators, a fingerprint, for example.
Popular rim locks
There are a lot of cheap overhead locks, but saving on price leads to a primitive and quick breaking and a negative attitude towards overhead locking devices in general.
According to reviews, the most popular in terms of price and quality are the locks of the Polish company GERDA. This company pays attention to the aesthetic function of its overhead locks. They are available not only in different colors, but also in several styles.
The Gerda ZN 100 and ZN 200 overhead cylinder lock is designed for entrance and interior doors, but has a sufficient degree of secrecy, is reliable in operation and is equipped with anti-slip ergonomic rotary handles.
Quality lever locks are produced by the Russian-Italian company CISA-Elbor. For example, "Elbor Sapphire" 1.09.56. MA with the fourth security class, 12 levers and the number of combinations exceeding 10 million
The coded padlock "Dori-4 classic" is the most famous product of the Sevastopol company DORI. It has no analogues in the world. Despite the fact that it is a combination lock, it can withstand impacts up to 500 kg and has two dozen useful functions.
There are many overhead locks for metal doors. They are also produced by well-known manufacturers who seriously care about their own reputation, and hence the high quality of their products. Choosing a castle, you need to carefully studyaccompanying documentation and check the quality of the mechanism. For example, clicks and rubbing indicate that the parts fit poorly and can lead to problems during operation.
